On 8/15/12 10:05 PM, Jungkee Song wrote:
> Having said that dictionary members are inherently optional by definition,
> is it meaningful (and valid) to mark optional fields as nullable?
Seems like it should be to me, yes.
> dicationary Foo {
> DOMString iWantToBeRequired = "Default";
> DOMString? iWantToBeNullable;
> DOMString iAmAlreadyOptional;
> };
>
> Do the two dictionary members "iWantToBeNullable" and "iAmAlreadyOptional"
> semantically make any difference?
Yes. The latter can either be unset or set to a string. The former can
be unset, set to a string, or set to null. Those are different things.
> I was thinking spec writers sometimes encounter situations where they would
> like to explicitly describe certain dictionary members are required while
> others are not.
Dictionaries can't have a required member via IDL, unless the member has
a default value....
Of course the prose can always call for throwing if a member is not set.
-Boris